SOLVABLE_BUILDTIME
ti = solvable_lookup_num(s, SOLVABLE_BUILDTIME, 0);
repodata_set_num(data, s - pool->solvables, SOLVABLE_BUILDTIME, t);
bt1 = solvable_lookup_num(s1, SOLVABLE_BUILDTIME, 0);
bt2 = solvable_lookup_num(s2, SOLVABLE_BUILDTIME, 0);